The Example in https://docs.oracle.com/en/database/oracle/oracle-database/23/sqlrf/SELECT.html#GUID-CFA006CA-6FF1-4972-821E-6996142A51C6__GUID-1B520407-DD06-4568-8E64-25F90F4C0B59 looks like this:
The example uses single quotes for the column alias. This does not work and throws the following error message in SQLcl 23.3:
Error starting at line : 1 in command -
SELECT
ename, mgr,
FIRST_VALUE(sal) OVER w AS 'first',
LAST_VALUE(sal) OVER w AS 'last',
NTH_VALUE(sal, 2) OVER w AS 'second',
NTH_VALUE(sal, 4) OVER w AS 'fourth'
FROM emp
WINDOW w AS (PARTITION BY deptno ORDER BY sal ROWS UNBOUNDED PRECEDING)
Error at Command Line : 3 Column : 34
Error report -
SQL Error: ORA-00923: FROM keyword not found where expected
00923. 00000 - "FROM keyword not found where expected"
*Cause: In a SELECT or REVOKE statement, the keyword FROM was
either missing, misplaced, or misspelled. The keyword FROM
must follow the last selected item in a SELECT statement or
the privileges in a REVOKE statement.
*Action: Correct the syntax. Insert the keyword FROM where
appropriate. The SELECT list itself also may be in error. If
quotation marks were used in an alias, check that double
quotation marks enclose the alias. Also, check to see if a
reserved word was used as an alias.
More Details :
https://docs.oracle.com/error-help/db/ora-00923/
The column alias should use double quotes or no quotes at all. Like this:
SELECT
ename, mgr,
FIRST_VALUE(sal) OVER w AS first,
LAST_VALUE(sal) OVER w AS last,
NTH_VALUE(sal, 2) OVER w AS second,
NTH_VALUE(sal, 4) OVER w AS fourth
FROM emp
WINDOW w AS (PARTITION BY deptno ORDER BY sal ROWS UNBOUNDED PRECEDING);
The documentation should be amended accordingly.